Electric drive machines and equipments such as hybrid electric vehicles (HEVs), electric vehicles (EVs), electric motorcycles, aircraft, and marine vessels include various output apparatuses such as motors, electric lights and indicators. Accordingly, an electric storage apparatus for supplying electric power to the output apparatuses is mounted on each electric drive machine and equipment.
The electric storage apparatus includes at least one electric storage device and an external housing for housing the at least one electric storage device. As a result, the electric storage apparatus secures electrical insulating properties by means of the external housing, while supplying the electric power corresponding to the number of electric storage devices to the output apparatuses.
There is known an electric storage apparatus that includes a first external housing for housing an electric storage device and a second external housing for housing the first external housing. The first external housing may randomly move inside the second external housing (the first external housing and the second external housing may collide against each other) due to an influence of vibrations generated when the electric storage apparatus is mounted on each electric drive machine and equipment. In order to prevent such an event, the first external housing and the second external housing are coupled to each other at a plurality of portions by coupling members such as screws.
As a result, the first external housing and the second external housing are kept at a given positional relationship, and form a double partition wall around the electric storage device. Accordingly, the electric storage apparatus of this type is excellent in durability (resistance to vibration), and the electric storage device can be reliably protected under a vibrational environment.
Meanwhile, in the electric storage apparatus of this type, the first external housing and the second external housing are coupled to each other at the plurality of portions by the coupling members as described above. Accordingly, when the first external housing is incorporated into the second external housing (the positional relationship between the first external housing and the second external housing is kept in a constant state) in the case of manufacture or maintenance check that requires disassembling, complicated coupling work (attachment work of the coupling members) must be made for the plurality of portions between the first external housing and the second external housing.